Background: Growth hormone deficiency (GHD) in paediatric and adult patients so currently necessitates long-term treatment and persistence with a daily s.c injection regimen.Taking the low compliance of injection into account, a long-acting GH formulation allowing for reduced the inconvenience and distress associated with daily injections.CPRC-Y is a PEGylated recombinant human growth hormone (rhGH) developed with the aim of prolonging the exposure leading to low frequency s.c.administration.In order to acquire the comparable efficacy of once-daily dose of native GH, the appropriate dose regimen of CPRC-Y should be investigated.Objective: The purpose of this research was to construct appropriate models to characterize population PK/PD profiles for CPRC-Y and native GH and simulate the insulin-like growth factors Ⅰ (IGF-1) level of different dose regimens of CPRC-Y.